Welt bar actuating mechanism for straight knitting machines



May- 29,1951 E. J. BERGER ETAL 2,554,655

WELT BAR ACTUATING MECHANISM FOR STRAIGHT KNITTING MACHINES Criginal Filed Feb. 12, 1948 2 Sheets-Sheet 1 ATTORNEYS.

INVENTbRS: Emzl CZBer Howardif M y 1951 I E. J. BERGER ETAL 2,5 5 WELT BAR ACTUATING MECHANISM FOR STRAIGHT KNITTING MACHINES 7 Original Filed Feb. 12, 1948 2 SheetsSheet 2 ,INVENTORS! W TNESSES 6) Emil JBer er,& J HowardK. est,

' ATTORNEYS.

Patented May 29, 1951 WELT BAR ACTUATING MECHANISM FOR STRAIGHT KNITTING MACHINES Emil J. Berger and Howard K. West, Lansdale,

Pa., assignors to DexdaleHosiery Mills, Lansdale, Pa., a corporation of Pennsylvania Original application-February 12, .1948, Serial No. 7,801., now Patent No. 2,519,875, dated August 22,1950. Divided and this application February 19, 1949, Serial No. 77,384

4 Claims. 1

This invention relates to mechanism useful in connection with straight knitting machines of "the Cotton type to automatically actuate the welt bars by aidof which stocking blanks or the like are drawn from the needles during the knitting of welt fabric, the present application being a division of a co-pending patent application,

'Ser. No. 7,807 filed by us on February 12, 1948,.

now Patent No. 2,519,875. Ordinarily in the operation of knitting machines of the kind referred to, the welt bars are manipulated manually to engage their hooks with the initial courses of the fabric upon temporary stoppage of the ma chines after the formation of such courses. This is an exacting and painstaking procedure, particularly with machines now commonly employed in theproduc'tion of fine "gauge fashioned hosiery, and, moreover, entails the employment of specially skilled help at high pay which adds very considerably to production'costs.

The chief aim of our invention is to overcome the foregoing drawbacks, which objective is realized in practice, as hereinafter more fully set forth, through provision of a simple and relatively inexpensive automatic mechanism capable, upon placement of the welt bar in proximity to the needles and starting of the machine, of accurately positioning the bar and advancing it so that its hooks enter centrally into the intervals between the needles to receive the initial course of fabric, and for subsequently retracting the bar to draw the fabric from the needles as theknitting proceeds.

Other objects and attendant advantages will appear from the following detailed description of the attached drawings, wherein Fig. 1 is a fragmentary view in transverse'section of a straight knitting machine conveniently embodying our improved welt bar actuating mechanism.

Fig. 2 is a fragmentary view in top plan looking as indicated by the angled arrow IIII Fig. 1.

Fig. 3 is a detail view in section taken as in-. dicated by the angled arrows III-'III in Fig. 2.

Fig. 4 is a view similar to Fig. 1 with the parts of the mechanism differently positioned, and

Fig. 5 is a fragmentary view in top plan corresponding to Fig. 4.

The knitting machine in so far as it is illustrated herein, is identical in construction with that disclosed in the co-pending application hereinbefore'mentioned, having a bar I I] with a series of hook needles II; a relatively movable bar H with a complementing series of points 13 for covering the needle hooks in stitch formation; 'a cooperative series of sinkers and dividers It and I 5 slidingly supported in a stationary bed l6; and a series of knockover bits I! anchored in a separate bar I8. These several cooperative instrumentalities are moved in concert during the knitting as and by means such as disclosed in the aforesaid application, said means having accordingly been omitted from the drawings.

The welt bar actuating mechanism with which the present invention is more particularly concerned, comprises a pair of laterally spaced rails 20 for slidably supporting the welt bar indicated at 2 l said rails being fixedly secured transversely of the top of the usual front bed 22 of the machine framework. As shown, the welt bar 2i is fitted with a series of hooks 23 which are adapted to be thrust between the needles ll so as to engage the initial course C of the knitting as in Fig. 1, the yarn being supplied by the longitudinally transversing feed finger indicated at 24 in Fig. 4, in a well known manner. In accordance with our invention, the Welt bar 2| is provided with end extensions 2 l a whereto are afiixed at the bottom, forwardly projecting skids 25 for engaging the rails 20, said skids being tapered to determine slight downward tilting of the welt hooks 23 as shown in Figs. 1 and 4. By coaction with the end extensions Zia of the welt bar 2|, fixed guards 26 along the outer sidesof the rails 20 assist in guiding said bar as it is manually slid onto the rails inward of the machine toward the needles I I as far as permitted by engagement of said extensions with upstanding stop projections 21a of a pair of retracting elements 21 disposed longitudinally of the outer sides of said rails between the latter and said guards. The retracting elements 21 are constrained to endwise movement in slots 28 formed in the lateral p'rojections 20a of the rails, see Figs. 2 and 3, and are yieldingly drawn outward by tension springs 29. The outward movement of the elements 21 is limited by engagement of stop shoulders 21b thereon with lateral projections 28a of the rails 20.

For the purpose of automatically moving the welt bar 2| into operative position relative to the needles I I, we have provided a pair of thrust elements in the form of bars 30 which are arranged longitudinally of the rails 20 and which normally bear on the top of bed 22 as shown in Fig. 4, with shoulders 30a at their bottom edges stopped against the inner edge of said bed. At their outer ends, the thrust bars 30 are pivotally connected at 3|, see Fig. 1, to arms 32 fast on a rock shaft 33 which is rotatably supported in fixed bearing brackets 34 on the bed 22. Also fast on the rock shaft 33 is a crank arm 35 from which a hooked element 36 is pivotally suspended. A spring 31 serves to normally keep the hook element 36 withdrawn, as shown in dot and dash lines in Fig. 1 from the path of a lateral stud 38 on one arm 39a. of a lever 39 which is medially fulcrumed to move about a fixed center 40. The lever 39 is subject to a spring 4|, and the other arm 3% thereof carries a roller 42 arranged to be engaged by a rotary cam 43 on the main cam shaft 46 of the machine. Upon movement of another rock shaft 45 in counterclockwise direction, a spring finger 46 thereon, by coaction with a pin 41 on the hook element 36, swings said element to contact stud 38 of lever 39 as shown in full lines in Fig. 1. Thus, as lever 39 is actuated by cam 43, the bars 3 are thrust inward as in Fig. 1, with a result that, through coaction of sloped cam notches 39b therein with fixed studs 48 projected inwardly from the rails 20, the forward ends of said bars are raised to engage the end extensions 2|a of the welt bar 2| from behind. As the movement continues, the welt bar 2| is pushed inward until its hooks 23 are positioned between the needles I! in readiness to receive the first course C of fabric loops drawn by said needles. During advance of the welt bar 2| as just explained, a spring finger 49 (Figs. 2 and displaces the inner ends of the adjacent thrust bars 39, which, in turn, contacts one end of the welt bar and shifts said bar so that the other end thereof bears against the contiguous guard 26 as in Fig. 2. 23 of the welt bar 2| are accurately positioned on center relative to the intervals between the needles As shown, each thrust bar 30 is provided with a flexible tongue 58 which, by reaction with the corresponding stud 48, limits the rise of the bar as it is thrust inward. The shaft 45 is adapted to be rocked by means of an arm 5| thereon and a connecting link 52, from a timing chain a timing drum such as disclosed in the parent application of which the present one is a division. As already pointed out, the parts 36, 46, 5| and 52 occupy the positions in which they are shown in dot and dash lines with the hook element 36 out of the range of the stud 38.

In preparation for the knitting of a stocking blank, the welt bar 2| is slid inwardly on the rails 29 by hand until it is intercepted upon encounter of its end projections 2|a with the stops Bio of the retracting elements 21, the latter being normally held fully withdrawn by the springs 29 with their shoulders 2Tb stopped against the lateral projections 29a of the rails 20. In being so placed, the guards 26 serve as guides to approximately center the welt bar 2| on the rails 20 in a manner readily understood from Figs. 2 and 5. The machine is thereupon started, and the thrust bars 30 are moved inward upon a partial anti-clockwise rotation of the rock shaft 45 which is attended by movement of the flexible finger :6 to shift the hook element 36 into the path of the stud 38 on lever 39, as shown in full lines in Fig. 1. Accordingly, as the lever 39 is actuated by the rotary cam 43 against the pull of spring 4|, the hook element 36 is drawn downward and, through the arms 35 and 32 on the shaft 33, causes the thrust bars 30 to be moved inward, with attendant advance of the welt bar 2| to the position in which it is shown in Fig. 1.

Before completion of the current rotation of In this way the hooks cam shaft 44, the needles sinkers l4, and dividers IE will be operated to form the starting course 10f the knitting over the hooks 23 of the welt bar 2| as in Fig.- 1.

As the roller 42 rides off the cam 43, the spring 4|, by pulling upward on the arm 39a of lever 39, causes a projection 390 on the latter to act upon the stud 41 and thereby lift the hook element 36 for restoration of the thrust bars 30 to the normal position of Fig. 4. Immediately thereupon, the rock shaft 45 is reversely'turned to its normal position, with attendant withdrawal of the flexible tongue 46 from the stud 41 of hook element 36 which is instantly retracted by the spring 31 from the stud 38 on lever 39 as shown in dot and dash lines inFig. 1. Upon recession of the thrust bars 30 as just explained, the welt bar 2| is released to the action of the retracting elements 21. By pull of the springs 29 upon the elements 21, the welt bar 2| is yieldingly urged outward to. draw the fabric away from the needles I! as the machine continues in operation. At sometime before the shoulders Zlb of the elements 21 reach the stop lugs 20a on the rails 2|], the machine attendant is obliged to connect the welt bar 2| to the draw straps 53 (Figs. 4 and 5) of the usual take-up mechanism (not shown) of the machine, said mechanism then taking over to draw the fabric from the needles until the end of the knitting cycle. It is of course to be understood that the rock shaft 45 is operated but once for each knitting cycle of the machine.

Having thus described our invention, we claim: 1. In welt bar actuating mechanism for straight knitting machines having a series of needles and instrumentalities cooperative with the needles in stitch formation, asupport uponwhich a hooked welt bar is adapted to be placed; means for automatically moving the welt bar inward on the support into operative relation to the needles and to so hold it temporarily to receive upon its hooks, the loops of the initial course of the knitting; and yielding draft means automatically operative upon subsequent release of the welt bar, to draw said bar outward on the support relative to needles as the machine continues with the knitting, said draft means including a pair of springpulled bars slidably guided for endwise movement at opposite sides of the support and respectively having upward projections adapted to be engaged by the opposite ends of the welt bar as the latter is moved inward upon the support, and operative, upon release of the welt bar, .to draw said bar outward as the machine continues with the knitting.

2. In welt bar actuating mechanism for straight knitting machines having a series of needles and instrumentalities cooperative with the needles in stitch formation, a support upon which a hooked welt bar is adapted to be placed; means for automatically moving the Welt bar inward on the support into operative relation with the needles and to so hold it temporarily to receive the initial course of loops of the knitting, said means including a pair of thrust elements which normally occupy a horizontal position level with the supporting means; means for actuating the thrust elements; and means operative as the thrust elements are actuated to lift their inner ends so as to engage the welt bar from behind in moving it into operative position.

, 3. The combination according to claim .2, in which the means for actuating the thrust elements includes a rotary cam; a lever constantly oscillated by the cam; a linkage system connected to the bars and including a member normally beyond the range of the lever; and means for momentarily moving said member into the path ,of the roller arm to efiect actuation of the thrust ing it laterally so that its opposite end bears against the other guard as said bar is moved toward operative position, on the support to insure entry of its hooks centrally into the intervals 5 between the needles.

EMIL J. BERGER. HOWARD K. WEST.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 15 2,238,192 Start Apr. 15, 1941 2,305,335 Wilders Dec. 15, 1942 2,396,263 Hof'mann Mar. 12, 1946 2,431,160 Bitzer Nov. 18, 1947 

